1. Field of the Invention:
This invention relates to conduit rodding or fishing methods and devices used in the electrical construction and related industries. More specifically it relates to fish tape attachments having conduit lubricating means and flexible loops for freeing frictionally restrained fish tapes.
2. Description of the Prior Art:
In the electrical construction industry as well as others such as cable TV and telephone, it is necessary to insert conductors into protective conduits. These conduits are often made inaccessible by walls, ceilings, and floors of a building, or earth in underground construction prior to the installation of the conductors. In order to install the conductors, a long semi-flexible rod or ribbon made of steel or plastic, called a fish tape is commonly used. The fish tape is manually pushed through the conduit and attached to the conductors. The conductors are then attached and pulled back through the conduit with the fish tape. Several problems become evident with the use of this procedure and the fish tape. One problem is the stoppage of the fish tape while being pushed through the conduit due to frictional drag of the fish tape against the interior walls of the conduit. A short, very flexible fish tape spring-leader attachment has in the past been attached to the free end of the fish tape to assist in starting the tape around bends while being pushed through the conduit. Often, both the fish tape and spring-leader will become stuck while being pushed. Some fish tapes and leaders have been manufactured having loop structures designed to be hooked by a second fish tape. The second fish tape, with a hook structure on the free end is pushed from the opposite opening of the conduit by a second worker. This second fish tape is used to hook the loop structure of the stuck tape or leader and pull it the remainder of the way through the conduit.
The frictional forces responsible for sticking the fish tape are present between conductors sliding against interior conduit walls when being installed. Lubrication has in the past, been applied to the conductors prior to entering the conduit to reduce friction and consequently the pounds of pull needed to move the conductors through the conduit. Too much fiction results in a great deal of pulling pressure needed to move the conductors. This high pulling pressure can result in damaging the insulation on the conductor; the conductor, or both. The problem with applying lubricant to the conductors as they are entering the conduit is that the lubricant is usually wiped off onto the sides of the conduit before the conductors reach the bends, the location where lubrication is most needed. Also, conductors are often pulled manually making it desirable to reduce the amount of work needed to install the conductors. These procedures and apparatuses although somewhat effective, still have room for improvement.
Two separate searches were conducted to produce past art patents concerning conduit lubricating devices and methods, and fish tape leaders having hookable loops.
The first search was conducted in the following classes and subclasses for conduit lubricating devices and methods:
254/134.3FT, 134.3R, 134.7, 184/15,1 16, and 19. PA1 1. Wilson was issued Pat. No. 3,035,817, on May 22, 1962, for "Fish Tape Snagger". PA1 2. Pat. No. 3,041,043, was issued to Harden, on June 26, 1962, for "Line Pull-Through Device". PA1 3. On July 11, 1967, Blume was granted Pat. No. 3,330,533, for "Twisted Hook Terminal For Roding Ducts".
The following patents represented devices which seemed most pertinent to my invention:
1. Pat. No. 4,137,623, was issued to Taylor on Feb. 6, 1979, for "Method and Apparatus for Dispensing Fluid in a Conduit".
2. Taylor was also issued Pat. No. 4,275,096, on Jun. 23, 1981, for a similar device.
3. On Oct. 9, 1984, Jonnes was issued Pat. No. 4,475,629, for "Method and Apparatus For Selectively Metering And Spreading Lubricant In A Conduit".
4. Pickett et al, was issued Pat. No. 4,569,420, on Feb. 11, 1986, for "Lubricating Method And System For Use In Cable Pulling".
The aforementioned devices are primarily concerned with lubricating the conduit prior to the passage of the electrical conductors after a fish tape or pull line has been installed through the conduit. No devices are provided for application of lubricant for the specific purpose of easing the initial installation of the fish tape or would they be suitable for such use. The above past art devices are uni-directional for lubricating the inner conduit walls, being effective only when pulled through a conduit since they are not structured in a manner that would allow them to be pushed. These devices are only useful after a pull line of some sort has been installed through the conduit.
The following past art patents represent devices concerned with fish tapes and fish tape attachments having loop structures and were found in the subsequent classes and subclasses; 254/134.3.
The above three patents teach conduit fishing or rodding devices with hookable structures. The hookable loop portion of the Wilson device is attached to the conductor attachment eye and must be removed before the conductors can be attached for pulling. If the loop structure were to be left on the eye of the fish tape or leader there would be less room to attach the conductors. Also the added bulk of the looped assemblage over the wires would pose a binding problem within the narrow limited space of the conduit. The Harden and Blume apparatuses would also need to be removed before pulling conductors through the conduit. These hookable loop structured devices are not suitable to be used as the wire pulling device. The worker apparently would have to anticipate getting stuck to use such a device. Most often he would try to push a standard fish tape through the conduit. If the fish tape got stuck, he would have to pull it out of the conduit, attach one of the aforementioned loop structured devices to it and push it back into the conduit. In any case, there is usually a second worker standing at the opposite end of the conduit waiting for the fish tape to exit so he can attach the conductors to be pulled through the conduit. Any delay in the installation of the fish tape causes a loss of time and a consequent loss of money in the form of wages.
I feel my invention not only overcomes the disadvantages presented in the previously mentioned past art patents but provides new and useful benefits not possessed by any related device.